Allow internal handling of parse errors to be turned off.

This allows exceptions for parse errors to be propagated to the caller.  Exiting
the program in parse is a bad idea generally, as we have no way of knowing what
cleanup needs to be done in the main program.

examples/Makefile.am

@@ -1,7 +1,7 @@
 
 noinst_PROGRAMS = test1 test2 test3 test4 test5 test6 test7 test8 test9 \
 			test10 test11 test12 test13 test14 test15 test16 \
-			test17
+			test17 test18
 
 test1_SOURCES = test1.cpp
 test2_SOURCES = test2.cpp
@@ -20,7 +20,8 @@ test14_SOURCES = test14.cpp
 test15_SOURCES = test15.cpp
 test16_SOURCES = test16.cpp
 test17_SOURCES = test17.cpp test17-a.cpp
+test18_SOURCES = test18.cpp
 
-INCLUDES = -I$(top_srcdir)/include
+AM_CPPFLAGS = -I$(top_srcdir)/include
 
 AM_CXXFLAGS = -Wall -Wextra

examples/test18.cpp

@@ -0,0 +1,24 @@
+#include <string>
+#include <iostream>
+#include <algorithm>
+#include "tclap/CmdLine.h"
+
+using namespace TCLAP;
+using namespace std;
+
+int main(int argc, char** argv)
+{
+	try {
+
+		CmdLine cmd("Command description message", ' ', "0.9", false);
+
+		cmd.setExceptionHandling(false);
+
+		cmd.parse(argc, argv);
+
+	} catch (ArgException &e) { // catch any exceptions
+		cerr << "error: " << e.error() << " for arg " << e.argId() << endl;
+		return 1;
+	}
+}
+

include/tclap/CmdLine.h

@@ -129,6 +129,11 @@ class CmdLine : public CmdLineInterface
 		 */
 		CmdLineOutput* _output;
 
+		/**
+		 * Should CmdLine handle parsing exceptions internally?
+		 */
+		bool _handleExceptions;
+		
 		/**
 		 * Throws an exception listing the missing args.
 		 */
@@ -281,6 +286,21 @@ private:
 		 *
 		 */
 		bool hasHelpAndVersion();
+
+		/**
+		 * Disables or enables CmdLine's internal parsing exception handling.
+		 *
+		 * @param state Should CmdLine handle parsing exceptions internally?
+		 */
+		void setExceptionHandling(const bool state);
+
+		/**
+		 * Returns the current state of the internal exception handling.
+		 *
+		 * @retval true Parsing exceptions are handled internally.
+		 * @retval false Parsing exceptions are propagated to the caller.
+		 */
+		bool getExceptionHandling() const;
 };
 
 
@@ -297,6 +317,7 @@ inline CmdLine::CmdLine(const std::string& m,
   _version(v),
   _numRequired(0),
   _delimiter(delim),
+  _handleExceptions(true),
   _userSetOutput(false),
   _helpAndVersion(help)
 {
@@ -444,6 +465,11 @@ inline void CmdLine::parse(std::vector<std::string>& args)
 			throw(CmdLineParseException("Too many arguments!"));
 
 	} catch ( ArgException& e ) {
+		// If we're not handling the exceptions, rethrow.
+		if ( !_handleExceptions) {
+			throw;
+		}
+		
 		try {
 			_output->failure(*this,e);
 		} catch ( ExitException &ee ) {
@@ -554,6 +580,16 @@ inline bool CmdLine::hasHelpAndVersion()
 	return _helpAndVersion;
 }
 
+inline void CmdLine::setExceptionHandling(const bool state)
+{
+	_handleExceptions = state;
+}
+
+inline bool CmdLine::getExceptionHandling() const
+{
+	return _handleExceptions;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 //End CmdLine.cpp
 ///////////////////////////////////////////////////////////////////////////////

tests/Makefile.am

@@ -67,7 +67,8 @@ TESTS = test1.sh \
 		test65.sh \
 		test66.sh \
 		test67.sh \
-		test68.sh
+		test68.sh \
+		test69.sh
 
 EXTRA_DIST = $(TESTS) \
 			 test1.out \
@@ -137,6 +138,7 @@ EXTRA_DIST = $(TESTS) \
 			 test65.out \
 			 test66.out \
 			 test67.out \
-			 test68.out
+			 test68.out \
+			 test69.out
 
 CLEANFILES = tmp.out

tests/test69.out

@@ -0,0 +1 @@
+error: Couldn't find match for argument for arg Argument: --bob

tests/test69.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Checks that parsing exceptions are properly
+# propagated to the caller.
+../examples/test18 --bob > tmp.out 2>&1
+
+if cmp -s tmp.out $srcdir/test69.out; then
+	exit 0
+else
+	exit 1
+fi
+